Hydraulic transmission power plants and liquid fuel injection devices for internal combustion engines



' Jan. 30, 1968 P. PANHARD 3,365,879 HYDRAULIC TRANSMISSION POWER PLANTSAND'LIQUID FUEL INJECTION DEVICES FOR INTERNAL COMBUSTION ENGINESOriginal Filed Nov. 19, 1965 5 Sheets-Sheet I.

5 l Q N i 564/ pan/2am! ATTORNEYS P. PA NHARD 3,365,879 HYDRAULICTRANSMISSION POWER PLANTS AND LIQUID Jan. 30, 1968 FUEL INJECTIONDEVICES FOR INTERNAL COMBUSTION ENGINES Original Filed Nov. 19, 1965 5Sheets-Sheet 2 R O N E v m Pqa/ l d/Marc! mam ATTORNEY S P. PAN HA RD3,365,879 HYDRAULIC TRANSMISSION POWER PLANTS AND LIQUID Jan. 30, 1968FUEL INJECTION DEVICES FOR INTERNAL COMBUSTION ENGINES Original FiledNov. 19, 1965 5 Sheets-Sheet 3 P. PAN HARD 3,365,879 HYDRAULICTRANSMISSION POWER PLANTS AND LIQUID 7 Jan. 30, 1968 FUEL INJECTIONDEVICES FOR INTERNAL (-OMBUSTION ENGINES Original Filed Nov. 19, 1965 5Sheets-Sheet 4 ATTORNEYS Jan. 30, 1968 P. PANHARD 3,365,379

HYDRAULIC TRANSMISSION POWER PLANTS AND LIQUID FUEL INJECTION DEVICESFOR INTERNAL COMBUSTION ENGINES Original Filed Nov. 19, 1965 5Sheets-Sheet 5 ATTORNEYS United States Patent ()fiice 3,365,8l PatentedJan. 36, 1968 3,365,879 HYDRAULIC TRANSMISSTUN POWER PLANT; AND LIQUIDFUEL INJECTEGN DEVICES 113R INTERNAL 'COMBUSTQEON ENGRNES Paul Panhard,Paris, France, assignor to Socicte Anonyme Andre Citroen, Paris, France,a French society Continuation of application Ser. No. 514,731, Nov. 19,

1965. This application Apr. 18, 1967, Ser. No. 633,671 Claims priority,application France, Nov. 25, 1%4, 996,284, 996,285 8 Claims. (Cl.nth-14) ABSTRACT (F THE DISILDSURE A hydraulic transmission power plantincluding an internal combustion engine having a cylinder and pistonslidable therein. A hydraulic generator is operatively connected to bedriven by the engine and includes-at least one tubular plunger riding ina liquid filled cylinder. A closed hydraulic circuit is provided from adelivery valve to a suction valve both of which are mounted on thegenerator cylinder. A hydraulic receiver is provided in the hydrauliccircuit and a. damping capacity is connected with said circuit upstreamof said suction valve and a further damping capacity is connected withthe hydraulic circuit downstream of said delivery valve. A holdingcapacity of variable volume is connected with said generator cylinderbetween said two valves. The capacities are arranged with theirrespective axes disposed in star-shaped arrangement about the axis ofthe hydraulic generator cylinder.

An internal combustion having a compression cylinder and an engineprovided with a tubular casing rigid with the engine cylinder head andextending coaxially therein, and a different sized, double headedmetering member therein coaxially slidable in said casing. A tubularplunger is provided rigid with the piston riding in said cylinder suchthat the plunger fits slidably about said casing. The casing and plungerare provided with at least one orifice and passage so that when thepiston nears its outer dead center, an annular space in the casingcommunicates with the engine compression cylinder so that the meteringmember is displaced by pressure applied on one end thereof to effectinjection into the engines cylinder 21 This application is acontinuation of application Ser. No. 514,731, filed Nov. 19, 1965.

The present invention concerns hydraulic transmission power plantsincluding an internal combustion engine, a hydraulic generator (or pump)having pistons (or plungers) and driven by said engine and a receiver(or hydraulic motor) fed from said generator and coupled with the partsto be driven by the power plant, which parts may comprise, inparticular, of wheels of an automobile vehicle on which the power plant:is fitted.

A-m'ain object of the invention is to provide a power plant of this typewhich is better adapted than those existing at the present time to meetthe requirements of practice, in particular concerning its simplicity ofconstruction.

A feature of the invention relates to power plants of this type wherethe cylinder, or at least one of the cylinders, of the hydraulicgenerator cooperates, on the one hand, with two damping capacitiesconnected, respectively, upstream of a suction valve and downstream of adelivery valve of said generator and, on the other hand, with a holdingcapacity branched between these two valves to receive a variable portionof the liquid ill delivered, on every cycle, from said hydraulicgenerator cylinder, thus determining a variable ratio of transmissionbetween said generator and said receiver. This feature consists inmounting the respective axes of said three capacities (two dampingcapacities and a holding capacity) in star-shaped fashion about thegeometrical axis of said generator cylinder, said three respective axesbeing advantageously located, at least approximately, in a planeintersecting said generator cylinder.

Advantageously, the internal combustion engine is of the double actiontype including a single free piston slidable in a cylinder having twoopposed cylinder heads, said free piston carrying, on either sidethereof, a rod constituting a plunger for the hydraulic generator, thecylinder of which is rigid with that of said engine, the unit formed bysaid two cylinders being free to oscillate in the axial direction abouta position of equilibrium and being thrown, on every motor stroke, in adirection opposed to that of the movement of the piston and rods unit,the displacements of said two units being inversely proportional totheir respective masses, the ratio of which advantageously averages 20/1(cylinder unit mass to piston and rods 'unit mass).

Another feature of the invention relates to power plants of theabove-mentioned type where the cylinder, or at least one of thecylinders, of the hydraulic generator communicates with a holdingcapacity consisting of a shell divided by a movable or deformablepartition into two chambers one of which communicates permanently withthe hydraulic generator upstream of the delivery valve thereof, whereasthe other chamber is placed in communication, at the end of everysuction stroke of the generator pistons, with a source of gas atvariable pressure, whereby, on every cycle, a first portion of theliquid delivered by the generator is admitted into the first-mentionedchamber of said holding capacity until the respective pressures onopposite sides of said delivery valve become equal to each other, afterwhich a second portion of the liquid delivered by the generator isdelivered through this delivery valve. This other feature of theinvention consists in making said movable or deformable partition in theform of a rubber (or other elastomer) membrane mounted on a rigidsupport constituted by a perforated tube and carrying on its end a checkvalve which cooperates wiih a seat disposed between the second-mentionedchamber and said source of gas at variable pressure, said check valvebeing mounted to open toward said second chamber.

A second aspect of the invention relates to feed devices for internalcombustion engines of the kind where liquid fuel is injected into thecylinders of said engines. The invention is more especially, but notexclusively, concerned with fuel feed devices for free piston enginesand more especially in the case where the pistons of said engines arerigid with the pistons or plungers of generators (or pumps) forhydraulic transmission systems.

The object of the second aspect is to provide a device of this kindwhich is simpler and less expensive in its construction.

According to the second aspect, the feed device is characterized by thecombination of at least three features which are as follows: First, in atubular sheath fixed with respect to the internal combustion enginecylinder, there is disposed a metering member consisting of a rodprovided with two heads slidable in fluid-tight contact with said sheathwith a limited length of stroke, the head nearest to the enginecylinder, hereinafter called big head, having a cross section greaterthan that of the other head and being subjected, on. its side farthestfrom said other head, to the pressure existing in the compressionchamber of said engine cylinder; secondly, a pipe for the feed of fuelunder low pressure through a check valve opens into the annular spacebetween the fuel metering member rod, as limited by said heads and thesheath that surrounds said rod; and, thirdly, said sheath is disposedinside a tubular plunger rigid with the engine piston and adapted toopen at least one orifice provided in said sheath, and thus to connectthe above-mentioned annular space with said compression chamber when theengine piston is near its Outer dead center position, whereby themetering member, which was fixed in position by the column of liquid insaid above-mentioned annular space, can be displaced by the gaseouspressure applied on the big head thereof and thus inject into the enginecylinder a volume of fuel equal to the difference between the volumesdisplaced respectively by said two heads.

A preferred embodiment of the invention will be hereinafter describedwith reference to the appended drawings, given merely by way of example,and in which:

FIG. 1a diagrammatically shows a power plant according to the invention,the hydraulic generator of which is shown in axial section, theleft-hand side of this section corresponding to the section line Ia1a ofFIG. 2a and the right-hand side of this section to the section line117-112 of FIG. 221;

FIG. 2a is a radial cross section on the line II--II of FIG. la; and

FIG. 3a is a curve illustrating the operation of this power plant.

FIG. 1 shOWS, with portions shown in elevation and portions in axialsection, a power plant according to the second aspect of the inventionwith a hydraulic transmission, made according to the invention;

FIG. 2 shows, on an enlarged scale and in axial section, a detail ofFIG. 1; and

FIG. 3 shows a portion of FIG. 2 but with a different position of theparts.

The hydraulic transmission power plant illustrated by FIGS. la, 2a, and3a is adapted to drive an automobile vehicle.

Concerning the general structure of the power plant, it is madeaccording to the indications of the French Patent No. 1,350,753 of Dec.15, 1962.

The system comprises the following elements:

(a) an internal combustion engine A;

(b) a hydraulic generator including two opposed groups each comprising acylinder 101, a plunger 102, a suction valve 193, and a delivery valve164, said hydraulic generator being driven by engine A as it will behereinafter explained;

(c) a receiver, or hydraulic motor, B, the intake of which is connected,through pipes such as 105' (FIG. 2a), with the delivery valves 1614 ofthe hydraulic generator and the delivery of which is connected, throughpipes such as 106 and a tank 107, with the suction valves 103 of saidhydraulic generator, said receiver B being coupled with the deliverywheels (not shown) of the vehicle;

(d) two damping chambers C and D communicating with each hydraulicgenerator cylinder 101, respectively upstream of the suction valve 103and downstream of the delivery valve 104 thereof; and

(e) a holding chamber E connected to each of the cylinders 101 of thehydraulic generator between valves 103 and 164.

The axes of the three chambers C, D, and E are disposed in star-shapedarrangement about the geometrical axis of each cylinder 101 andpreferably, as shown, in a plane intersecting this cylinder.

Each of the capacities C and D comprises a bell-shaped vessel 108 and abase portion 109 between which is tightly held a diaphragm 110 thedeformations of which are limited in both directions by rigid perforatedcupshaped supports 111 and 112. In the drawings, the reference numeralsof the elements relative to capacities C and D are followed by lettersand d, respectively. In each base portion 169 there is provided a valveseat 113 cooperating with valve 1553 or 1114. Capacity E comprises anexternal shell 114.

Each bell-shaped vessel 1180 is subjected, through a pipe 137, to agaseous pressure corresponding to the mean valve of the suction, andevery bell-shaped vessel 168d is subjected, through a pipe 13-8, to agaseous pressure corresponding to the mean delivery pressure.

As shown by FIG. 2a, bell-shaped vessels 1080, 108d and 114corresponding to a cylinder 1111 of the hydraulic generator may be fixedupon the same block 115 through nuts 116 or 117 in such manner thattheir respective axes makes an angle of about degrees with one anotherin a plane perpendicular to the axis of said cylinder 101, whichcylinder is itself formed in block 115. Said block 115 further carriesthe suction and delivery connections 118a and 118d for pipes 1136 and105, respectively.

Each of the holding chambers E comprises a bellshaped shell 114 and amovable or deformable partition 1211 which separates the inside of saidshell 114 into two chambers 119 and 121 chamber 119 being connectedpermanently through an orifice 126 with the portion of the correspondingcylinder 101 between valves 10?) and 104, whereas chamber 120 is placedin communication, at the end of every suction stroke of plunger 102,with a source S of gas under variable pressure, this pressure beingpreferably proportional to the torque supplied by engine A.Advantageously, this source S is made as indicated in French Patent No.1,350,753. Deformable partition 121 consists of a membrane, for instanceof rubber, surrounding a perforated rigid tube 122. fixed in shell 114coaxially therewith. Membrane 121 carries, fixed to the bottom thereof,a check valve 123 the seat 124- of which is rigid with shell '114 and isinterposed between chamber 120 and gas source S. To the bottom end oftube 122 there is fixed an ogive 125 in the bottom portion of whichthere is' provided a cylindrical housing communicating through a passage127 with chamber 119 and accommodating a piston '127 subjected to theaction of a spring 128 and bearing against the bottom of membrane 121,so that check valve 123 closes during the delivery stroke of plunger 102as soon as the pressure of oil in chamber 119 is equal to that of thegas present in chamber 120' and reopens during the suction stroke ofplunger 102.

Thus, on every cycle, the first portion of the liquid de livered by aplunger 1152 is admitted into chamber 119', causing membrane 121 toexpand and to compress the gas present in chamber 1211, check valve 123being then closed. Then the respective pressures on the opposed sides ofdelivery valve 104 become equal. Delivery valve 104 then opens, and thesecond portion, i.e., the remainder of the liquid driven by plunger1112, is discharged past said valve 194. The power supplied to receiverB and the ratio of transmission depend upon the respective values of thetwo above-mentioned liquid portions and, therefore, upon the pressure ofsource 15. During the next suction stroke of plunger 102, the energycorresponding to the compression of gas in chamber 120 is restored tosaid plunger 102. Then check valve 123 reopens.

As shown by FIGS. 1a and 2a, membrane 121 and tube 122 are held betweenbell-shaped shell 1 14 and block 115 by means of nut 117.

The internal combustion engine A is of the double action type andincludes a single free piston 129 mounted in a cylinder 139 having twocylinder heads 136. This piston 129 carries, fixed thereto on eachopposite side thereof, a rod 102 forming a plunger for the hydraulicgenerator, each cylinder 1611 of which is formed in a block 115 rigidwith cylinder 130. The unit formed by cylinder 131), blocks 1-15 and theparts rigid therewith is arranged to be freely oscillable in the axialdirection, about a position of equilibrium, by being thrown, on everymotor stroke, in a direction opposed to that in which oscillates theunit formed by piston 129 and rods 102, the displacements of the twounits being inversely prooprtional to their respective masses.Advantageously, the ratio of the mass of the first unit 130-115 and ofthe mass of the second unit 129 1112 averages 20/1.

In order to enable the first unit to move freely in this manner, it maybe suspended, through parallel connecting rods 131, to spindles 132carried by a fixed frame. When these connecting rods 131 are disposed oneither side respectively, of the movable unit (as shown by FIG. 111),most of the surface of this unit is free and can be fitted with coolingtins 133 of large dimensions. Besides, cooling is improved by the factthat the cylinder unit is moving in air.

FIG. 1a shows an intake pipe 134 and an exhaust pipe 135 for internalcombustion engine A, the respective ports corresponding to said pipesbeing controlled by piston 129. These ports may be the same for bothsides of the engine or, as shown by the drawings, be separate if it isdesired to give them an inclination in order to improve the guiding ofthe gaseous streams and to reduce the temperature of the cylinder atthis place. The fuel feed system and possibly the ignition system havenot been shown in the drawings and may be of any type applied in thecase of free piston engines. The whole of piston 129 and plungers 102 isshown in solid lines on the right-hand side, i.e., near the end of therightward stroke of the piston. The end of the leftward stroke of saidpiston is shown in dot-and-dash lines on the left-hand side of FIG. 1a.

In the embodiment illustrated by FIGURES 1a, 2a, and 3a of the drawings,the movable unit includes, on either side, star-disposed capacities C,D, and E. Pipes 105 and 106 must include a flexible portion in order topermit the displacement of said movable unit.

In the case where the power plant is intended to be used on anautomobile vehicle, the group shown in FIG. 1a is preferably disposed insuch manner that the axis of cylinder 130 corresponds to the axis ofmaximum inertia of the support, that is to say, to the longitudinal axisof the vehicle.

The operation and the advantages of the power plant according to theinvention are as follows:

The operation is very different from that of usual free piston engines.

As a matter of fact, in said engines, in order to obtain a goodbalancing, use is made of two opposed pistons mounted in a commoncylinder and which oscillate under the effect of two forces. Theseforces are, on the one hand, that resulting from the combustion of thefuel and air mixture, and on the other hand, a resilient return forcecapable of supplying the energy necessary for com pression of thismixture. For practical purposes, such an arrangement is suitable forengines running at nearly constant speed, because the variable load isbalanced by injecting a variable amount of fuel.

On the contrary, in the internal combustion engine according to theinvention, piston 1'29 oscillates constantly between two exactlysymmetrical and simultaneously variable forces, the piston receivingalways on one of its end faces the energy of explosion or combustion,whereas the other end face serves to compress the mixture or an amountof air, and plunger 102, which forms an extension of said piston,supplies a hydraulic work identical for every half stroke thereof.

If the operation is analyzed by calculation, it is found that it ispossible, While maintaining a constant stroke of the piston, to vary thenumber of reciprocations thereof per minute to a considerable degree andthat to every speed of reciprocation corresponds an exactly given power.

Calculation for an engine having a cylinder bore of 85 mm. and a strokeof 75 mm. shows, for instance, that with a weight of the piston movableunit equal to 1.250 kgs, the number of reciprocations for a power equalto zero is about 2600, whereas it passes to 3600 for a power of HPcollected hydraulically, to 4200 for HP and to 4600 for HP.

If such a unit is mounted on a vehicle where the hydraulic receiver Brequires 2600 reciprocations at full rate at a speed of kin/11., it isseen that, for all speeds below 95 km./h., one may apply to the wheels apower varying 6 from 0 to 60 HP (with the restriction that the adhesionat very small speed practically does not permit utilization of all thepower that is available).

Above 95 km./h., it is not possible to utilize the powers ranging from 0HP to the minimum power corresponding to full rate at the correspondingnumber of reciprocations. This is visible on FIG. 3a.

This figure shows, at a, the curve (in dotted lines) giving the relationbetween the number or" reciprocations (N per minute) and the powersupplied by the engine (p in HP) which is a characteristic of this kindof engine.

Curve 1; shows (in solid lines) the curve of the power necessary forobtaining a predetermined speed of the vehicle (V in km./h.).

The ordinate AA corresponding to the speed of km./h. intersects curve aat H and curve b at M. It is seen that, at 120 krn./h., the number ofreciprocations at full rate is 3295 and the power is 12 HP. It followsthat, at 120 km./h., it is possible to use all the powers ranging from12 to 60 HP. In a likewise manner at km./h. the power available rangesbetween 26 and 60 HP.

As it is an important condition that every speed can be maintainedwithout either acceleration or slowing down, curve a must not intersectcurve 1) within the whole zone of possible use of the vehicle.

The invention does not require: the use of devices such as crank shafts,connecting rods or any other mechanisms for transforming the movement.It permits, at a cost much lower than that of conventional systems(engine-clutchgear-box transmission), obtaining an operation which isautomatic in all circumstances, the driver adjusting merely the powerbrought into play in engine A, without having to intervene otherwise ifthe gradient of the road or the driving circumstances undergomodifications. The power plant is very compact and permits reducing thespace generally reserved for the engine and its accessories. Finally,the freedom of the power cylinder avoids the usual reactions upon thebody of the vehicle and increases the comfort of the passengers byreducing vibrations and noises.

The system illustrated in FIGURES 1, 2 and 3 comprises the followingelements:

(a) An internal combustion engine A;

(b) A hydraulic generator (or pump), including two opposed groups eachcomprising a cylinder 1, a plunger (or rod) 2, a suction valve 3 and adelivery valve 4, said hydraulic generator being driven by engine A, asit will be hereinafter explained;

(c) A receiver, or hydraulic motor, B the intake of which is connected,through pipes 5, with the delivery valves 4 of the hydraulic generatorand the delivery of which is connected, through pipes 6, with thesuction valves 3 of said hydraulic generator, said receiver B beingcoupled with the delivery wheels (not shown) of the vehicle;

(d) Two damping chambers C and D communicating with each cylinder 1 andconnected respectively upstream of the suction valve 3 and downstream ofthe delivery valve 4 thereof; and

(e) A holding chamber E connected to each of the cylinders 1 betweenvalves 3 and 4 so as to receive a variable portion of the liquiddelivered on every cycle from said cylinder 1, thus determining theratio of transmission between engine A and receiver 13.

According to the disclosure of the invention of FIG- URES la, 2a, and 3aherein, and the invention disclosed in [1.8. Patent application Ser. No.508,670, filed Nov. 19, 1965, in the same name, the three chambers C, Dand E are disposed in star-shaped manner about the geometrical axis ofeach cylinder it and preferably at the same transverse level as thiscylinder. In FIG. 1 the cross section plane for the upper part of thedrawing is the same for both of the units and therefore shows both ofthe chambers D located on the right hand and on the left hand, whereasthe cross sections corresponding to the lower portion of FIG. 1 aremade, respectively for the right-hand side and the left-hand side,through two planes symmetrical with respect to said vertical plane andmaking between them an angle of 120 degrees so that the lefthand portionshows a chamber E and the right-hand portion a chamber C.

According to the disclosures referred to in the preceding paragraph, theinternal combustion engine is of the double-action type and includes asingle free piston 7 mounted in a cylinder 8 having two cylinder heads9. This piston carries, fixed thereto on each opposite side thereof, aplunger or rod 2 and the hydraulic generator cylinders 1 cooperatingwith said rods 2 are provided in blocks 10 rigid with cylinder heads 9.The whole of cylinder 8, cylinder heads 51 and blocks 10 is arranged tobe freely oscillable along its axis in a direction opposed to that inwhich oscillates the whole of piston 7 and plungers 2. The internalcombustion engine intake pipes are designated by reference numeral 11and the exhaust pipes by 12, the corresponding ports being controlled bypiston 7.

Referring new again to FIGS. l3, herein, the liquid fuel feed device ofthe internal combustion engine is made, on either side of piston 7, inthe following manner:

There is disposed, inside a tubular sheath 14, fixed with respect tocylinder 8, a metering member 15 consisting of a rod 15a provided withtwo heads 15]) and 150 adapted to slide, with a limited amplitude, influid-tight contact with the inner face of sheath 14 and with a surfacein line therewith provided in a cap 16 fixed to block 10. The crosssection S of the head 15b nearer the cylinder 8 is greater than thecross section s of the other head 15c and it is acted upon, on itssurface farthest to said other head (on the left-hand side in FIGS. 2and 3) by the pressure existing in the compression chamber 34 ofcylinder 8.

A fuel feed pipe 18 for fuel under pressure, provided with a check valve19, opens into the annular space 17 between sheath 14 and the rod 15a ofmetering member 15 (between heads 15b and 150).

Sheath 14 is located inside a tubular sleeve rigid with piston 7 andcapable, when piston 7 is nearing its outer dead center position (i.e.,its extreme position toward the right in FIGS. 2 and 3), of openingorifices 21 and 22 provided in sheath 14 so as thus to connect theannular space 17 with the compression chamber 34.

In the embodiment of the invention illustrated by the drawings, cap 16is fixed to block 10 through bolts 23 and nuts 24, sheath 14 beingwelded to cap 16. Said cap is provided with a bore 25 of a diametersmaller than the inner diameter of sheath 14, and intended toaccommodate the small head 150 of metering member 15.

The above-mentioned tubular sleeve rigid with piston 7 is formed by theplunger 2 of the hydraulic generator, whereby the useful pumping crosssection of this plunger 2 is reduced by an amount equal to the externalcross section of sheath 14.

Said tubular plunger 2 includes, on its inner wall, a sleeve 26 securedthereto by means of a nut 2tl, the inner edge of said sleeve 26 beinglocated on the left of orifices 21, 22 when the internal combustionengine piston 7 is in its outer dead center position (FIG. 2). Means areprovided for making fluid-tight, on the one hand, the surfaces ofcontact (without relative sliding displacement) between the inner wallof plunger 2 proper and the outer wall of sleeve 26 and, on the otherhand, the surfaces of contact (with sliding relative displacement)between the inner wall of sleeve 26 and the outer wall of sheath 1 so asthus to separate from each other the fuel circuit and the transmissionliquid circuit.

In order to limit the displacement of metering member 15 with respect tofixed sheath 14, there is provided, on the one hand, at the end of thebig head 15b, a flange 27 projecting to the outside of sheath 14 and, onthe other hand, at the end of the small head 150, a washer 28cooperating with a fixed but adjustable abutment. Such an abutmentconsists, in the embodiment illustrated by the drawings, of the innertransverse face of a hollow screw 29 through which small head extendsand which is engaged in a threaded portion of cap 16, said screw 29being rigid with a manually or automatically controlled lever 30.

In order to permit the pressure existing in the compression chamber 34of cylinder 8 to be transmitted to the big head 151), there is providedat least one passage 31 connecting the external surface of piston 7 withthe inside of tubular plunger 2, this passage being provided in an axialplane and being slightly inclined, as shown by FIG. 2 so as to opentangentially to the curved end face of piston 7.

As shown there is further provided, in the wall of tubular plunger 2, atleast one fuel injection passage 32, positioned to open oppositeorifices 21 and 22 when piston 7 is close to its outer dead centerposition. Passage 32 may open directly into chamber 34 but preferably,as shown by the drawings, it opens into an annular turbulence chamber 33provided in cylinder head 9 and surrounding plunger 2.. Advantageously,as shown, said orifice 32 is inclined from the inside toward the outsidein the direction away from piston 7 so as to open tangentially to theportion of the wall of chamber 33 that is most remote from piston 7.Advantageously, as shown, sleeve 26 has a bevelled edge 26a in line withthe corresponding edge of orifice 32.

The feed device above described works as follows:

If it is supposed that area S is equal to 24 rnm. (diameter of about 5.5mm.) and that area s is equal to 16 mm. (diameter of about 4.5 mm.), fora displacement of metering member 15 of 1 mm. toward the left of FIGS. 1and 2, the volume of annular space 17 increases by (2416) mm. 1 mm.=8mm. If the maximum stroke of metering member 15 is supposed to be 5 mm.,the maximum volume of fuel displaced by said metering member is fivetimes greater, that is to say 40 mmfi. Fuel is fed through pipe 13 undera relatively small pressure (some kgs./cm. which overcomes the inertiaof the fuel column and the inertia of metering number 15. In order toreduce this last-mentioned inertia, the metering member may be made of alight metal so as to have a weight of only some grams. Besides, the end15d of metering member 15 may be pushed by a small spring if it isdesired to reduce the pressure of the fuel arriving through pipe 18.

When the pressure has dropped in chamber 34, which occurs when piston 7is near its inner dead center position, i.e., toward the left of FIGS. 2and 3, the pressure in pipe 18, possibly added to the action of thelast-mentioned spring, opens check valve 19 and pushes metering member15 toward the left of FIGS. 2 and 3 until washer 28 comes into contactwith hollow screw 29. There is thus admitted into annular space 17 avolume of fuel proportional to the displacement 1 of metering member 15,which displacement is adjusted by lever 39, that is to say a volume of8X1 mm. in the example that has been considered (1 being expressed inmillimeters).

At the end of the compression stroke in cylinder 8, the pressure incompression chamber 34 is transmitted through orifice 31 to the big head15b of metering member 15. As soon as the movement of piston 7 andplunger 2 causes the bevelled edge 26a of sleeve 26 to clear orifice 21(FIG. 3), metering member 15, which was kept in position by the columnof fuel enclosed in annular space 17, is released and driven toward theright by said pressure in chamber 34 until orifice 21 is closed.

A portion of said volume of fuel is injected. The injected fuel, drivenby the air stream through passages 31 and 32 (as shown by the arrows ofFIG. 3), mixes with air in turbulence chamber 33, where it is ignitedeither by suitable ignition means, or, when the compression ratio issufficiently high, by spontaneous ignition.

When orifice 22 is subsequently cleared (near the outer dead centerposition, FIG. 2), the remainder of said fuel volume is injected and, atthis time, the combustion in 9 chamber 33 reverses the direction of fiowthrough passages 32 and 31 (as shown by the arrows of FIG. 2) and causesan ignited fuel mixture to be injected into compression chamber 34 whereit finds the amount of air necessary to finish its combustion.

When, at the beginning of injection, there is, for instance, a pressureof 5 kgs./cm. in compression chamber 33, 34, this pressure acts uponhead 15b (area S is equal to 24 mm. as above indicated. As the area s ofhead 150 is 16 mm. the pressure exerted by the fuel contained in annularspace 17 is equal to =15 kgs./cn1.

As soon as orifice 21 is opened, fuel is injected under the differenceof the pressures existing respectively in said space 17 and in chamber33, which difference is equal to kgs./cm. The pressure at the end ofinjection may be much higher (either end of compression or beginning ofcombustion).

If the stroke and, consequently, the volume of fuel that is injected aresmall (case of low loads), the orifice 21 of FIG. 3 remains covered byhead b and injection takes place only when orifice 22 is cleared bysleeve 26. Combustion takes place only in chamber 33, which ensures acorrect operation even with an explosion cycle, the richness of fuel inthe mixture being then sufiicient, since only a small portion of the airadmitted into cylinder 8 is mixed with fuel.

It will be noted that, since plunger 2 is surrounded with the oil of thehydraulic transmission device (under pressure during the deliverystroke), the operation remains correct even with a fuel (gasoline)having bad lubricating properties.

To sum up, the fuel injection device according to the present inventionperforms the same functions as the conventional fuel injection devices,but with a greater simplicity and at a lower cost.

In a general manner, while the above description discloses what isdeemed to be a practical and efiicient embodiment of the presentinvention, said invention is not limited thereto as there might be.changes made in the arrangement, disposition and form of the partswithout departing from the principle of the invention as comprehendedwithin the scope of the appended claims.

What is claimed is:

1. A hydraulic transmission power plant which comprises, in combination,

an internal combustion engine comprising a cylinder and a pistonslidable in said cylinder,

a hydraulic generator comprising at least one tubular plungeroperatively connected with said engine piston and a cylinder adapted tocooperate with said plunger, said hydraulic generator cylinder beingfilled with a liquid,

a delivery valve mounted on said generator cylinder,

a suction valve mounted on said generator cylinder,

a closed hydraulic circuit extending from said delivery valve to saidsuction valve,

a hydraulic receiver in said hydraulic circuit,

a damping capacity connected with said circuit upstream of said suctionvalve,

a damping capacity connected with said circuit downstream of saiddelivery valve,

21 holding capacity of variable volume connected with said generatorcylinder between said two valves, and

means for varying said holding capacity variable volume,

said three capacities having their respective axes disposed instar-shaped arrangement about the axis of said hydraulic generatorcylinder.

2. A power plant according to claim 1 wherein the respective axes ofsaid three capacities are located substantially in a plane intersectingsaid hydraulic generator cylinder.

5 kgs./cm. X

3. A hydraulic transmission power plant which cornprises, incombination,

a double action internal combustion engine comprising a cylinder havingtwo opposed cylinder heads and a single free piston slidable in saidcylinder.

a hydraulic generator comprising at least one tubular plunger rigid withsaid piston and a cylinder, rigid with said internal combustion enginecylinder, adapted slidably to accommodate said plunger, said hydraulicgenerator cylinder being filled with a liquid,

a delivery valve mounted on said generator cylinder,

a suction valve mounted on said generator cylinder,

a closed hydraulic circuit extending from said delivery valve to saidsuction valve,

a hydraulic receiver in said hydraulic circuit,

a damping capacity connected with said circuit upstream of said suctionvalve,

a damping capacity connected with said circuit down stream of saiddelivery valve,

a holding capacity of variable volume connected with I said generatorcylinder between said two valves, and means for varying said holdingcapacity variable volume,

said three capacities having their respective axes disposed instar-shaped arrangement about the axis of said hydraulic generatorcylinder.

4. A power plant according to claim 3 wherein the Whole of saidcylinders forms a unit capable of oscillating freely in the axialdirection about. a position of equilibrium, said unit being thrown, onevery motor stroke, in a direction opposed to that of the movement ofthe unit formed by said piston and said rods, the displacements of saidtwo units being in inverse ratio to their respective masses.

5. A power plant according to claim 4, wherein the ratio of the mass ofthe first unit to that of the mass of the second unit approximates 20.

6. A power plant according to claim 4 for use in an automobile vehicle,wherein the axis of the internal combustion cylinder and of thehydraulic generator cylinders corresponds to the maximum inertia axis ofthe support, i.e., to the longitudinal axis of the vehicle.

7. A hydraulic transmission power plant which comprises, in combination,

an internal combustion engine comprising a cylinder and a pistonslidable in said cylinder,

a hydraulic generator operatively connected with said engine so as to bedriven by it and comprising at least one tubular plunger and a cylinderadapted slidably to accommodate said plunger, said hydraulic generatorcylinder being filled with a liquid, delivery valve mounted on saidgenerator cylinder, suction valve mounted on said generator cylinder,closed hydraulic circuit extending from said deivery valve to saidsuction valve,

a hydraulic receiver in said hydraulic circuit,

a liquid holding capacity connected with said generator cylinder betweensaid valves, said liquid holding capacity including:

a rigid shell,

a resilient deformable membrane of general tubular shape mounted in saidshell to divide it into two chambers, a first one and a second one, saidfirst chamber being in permanent free communication with said generatorcylinder,

a rigid perforated tube fixed in, said shell inside said membrane forlimiting the inward deformations thereof,

a valve seat carried by said shell and opening into said second chamber,

a source of gas under variable pressure arranged on the outside of saidshell and adapted to communicate with said second chamber through saidvalve seat,

a check valve adapted to cooperate with said valve seat and openingtoward the inside of said shell into 1 1 said second chamber thereof,said check valve being carried by the end of said membrane so as to beapplied on said seat when said membrane expands, and means responsive tothe pressure in said first chamber for opening said check valve inresponse to a suction in said first chamber.

8. A power plant according to claim 7 further comprising a rigid ogivefixed to said tube, said ogive having a flat base located substantiallyin the same plane as the free end of said tube and the point of saidogive being turned toward said generator cylinder, said ogive beingprovided with a cylindrical recess opening in the direction of saidcheck valve, a piston slidable in said cylindrical recess and bearingagainst the end of said mem- References Cited UNITED STATES PATENTSFraser 123-4399 Petersen 123-1399 Van Der Lely et al. 10354 Johnson eta1 60-44 Anderson et al. 6019 WENDELL E. BURNS, Primary Examiner.

